1. Field of Application
This invention relates to illumination of curved surfaces; and more particularly to illumination of round, reflective, cylindrical parts of curved surfaces.
2. Description of the Prior Art
It is often necessary in Machine Vision to light or illuminate round, reflective, cylindrical parts of curved surfaces evenly enough to read date and lot codes and other symbology such as data matrix marks, or to be able to inspect such parts for flaws like: gouges; dents; scratches; etc. Some illumination devices, particularly those commonly referred to as continuous diffuse illuminators (CDI): are shown, and described, by way of example in U.S. Pat. No. 5,461,417 patented to T. P. White, et al on Oct. 24, 1998 for “Continuous Diffuse Illumination Method and Apparatus”. Other similar illuminators are shown and described, for example, in other ones of U.S. Patents to T. P. White under U.S. Pat. Nos. 5,539,485; 5,604,550; 5,684,530; and 5,713,661 respectively.
Other CDI's, and quoted light sources, that may provide uniform illumination of curved surfaces typically require a complex structure of multiple lighting sources and optical elements like beamsplitters, reflecting domes and light blocks. They may also dictate a rigid camera location.